Company Operations by Product, Customer and Geographic Area - Revenue by Significant Customer (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Total revenues	$ 59,215	$ 103,269	$ 173,245
Wholesaler Customer
Segment Reporting Information [Line Items]
Total revenues	59,215	101,423	172,841
Cardinal Health | Wholesaler Customer
Segment Reporting Information [Line Items]
Total revenues	15,088	25,413	37,965
McKesson Corporation | Wholesaler Customer
Segment Reporting Information [Line Items]
Total revenues	14,900	26,794	44,762
AmerisourceBergen | Wholesaler Customer
Segment Reporting Information [Line Items]
Total revenues	12,059	18,620	25,691
Others | Wholesaler Customer
Segment Reporting Information [Line Items]
Total revenues	17,168	30,596	64,423
License revenue
Segment Reporting Information [Line Items]
Total revenues	0	1,846	404
License revenue | Wholesaler Customer
Segment Reporting Information [Line Items]
Total revenues	$ 0	$ 1,846	$ 404